Calculus with Applications (10th Edition)

Published by Pearson
ISBN 10: 0321749006
ISBN 13: 978-0-32174-900-0

Chapter 8 - Further Techniques and Applications of Integration - Chapter Review - Review Exercises - Page 455: 25

Answer

The area is bounded by $$ \left( y=x^{3}(x^{2}-1)^{\frac{1}{3}}, \quad y =0, \quad x=1, \quad x=3 \right) $$ is equal to $$ \int_{0}^{1} x^{3}(x^{2}-1)^{\frac{1}{3}}dx=\frac{234}{7}\approx 33.43 $$

Work Step by Step

The area is bounded by $$ \left( y=x^{3}(x^{2}-1)^{\frac{1}{3}}, \quad y =0, \quad x=1, \quad x=3 \right) $$ is equal to $$ \int_{0}^{1} x^{3}(x^{2}-1)^{\frac{1}{3}}dx $$ First, we evaluate the indefinite integral as follows: $$ \int x^{3}(x^{2}-1)^{\frac{1}{3}}dx $$ use integration by parts with $$ \quad\quad\quad \left[\begin{array}{c}{u=x^{2}, \quad\quad dv= x(x^{2}-1)^{\frac{1}{3}}dx } \\ {d u= 2xdx, \quad\quad v= \frac{3}{8}(x^{2}-1)^{\frac{4}{3}}dx }\end{array}\right] , $$ then $$ \begin{aligned} \int x^{3}\left(x^{2}-1\right)^{1 / 3} d x&=\\ &=\frac{3 x^{2}}{8}\left(x^{2}-1\right)^{4 / 3}-\frac{3}{4} \int x\left(x^{2}-1\right)^{4 / 3} d x \\ &=\frac{3 x^{2}}{8}\left(x^{2}-1\right)^{4 / 3}-\frac{3}{4}\left[\frac{1}{2} \cdot \frac{3}{7}\left(x^{2}-1\right)^{7 / 3}\right] \\ &=\frac{3 x^{2}}{8}\left(x^{2}-1\right)^{4 / 3}-\frac{9}{56}\left(x^{2}-1\right)^{7 / 3}+C \\ \end{aligned} $$ Now we will evaluate the definite integral as follows: $$ \begin{aligned} A &=\int_{1}^{3} x^{3}(x^{2}-1)^{\frac{1}{3}}dx \\ &=\left.\left[\frac{3 x^{2}}{8}\left(x^{2}-1\right)^{4 / 3}-\frac{9}{56}\left(x^{2}-1\right)^{7 / 3}\right]\right|_{1} ^{3} \\ &=\frac{3}{8}(144)-\frac{9}{56}(128) \\ &=54-\frac{144}{7} \\ &=\frac{234}{7} \\ &\approx 33.43 \end{aligned} $$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.